1. Field of the Invention
This invention relates generally to the containers used in the transport of chemicals and, more particularly, to the temporary repair of damaged cylinders used in the transport or storage of pressurized chemicals.
2. Discussion of the Related Art
Gases, such as chlorine, carbon dioxide and ammonia are generally supplied in a liquid state, confined under pressure in containers of a plurality of sizes. In particular, the ton container is popular for storage and transport of pressurized chemicals and has a configuration shown in FIG. 1. The ton container 10 is generally cylindrical shape, having cylindrical walls 17. At either end of the ton container 10 is an end member 11, that is recessed with respect to the ends of the cylinder walls and coupled to the cylindrical walls. In addition, the ends of the cylindrical walls, 17a, extend beyond the union with the end members 11 and are tapered. A plurality of fusible metal plugs 12 are typically inserted in the end member 11 for the purpose of preventing an explosion of the container by melting and thereby permitting the release of gas in the event of excessive heating of the cylinder. The cylindrical ton containers are typically stored in a horizontal position and typically have two valves 14 coupled to eduction pipes 15. In practice, the valves are stored in a vertical line so that the upper valve can release a gas phase of the stored chemical, 5A, while the lower valve will release liquid phase of the stored chemical, 5B. Although the integrity of the cylindrical members is seldom imperiled, there are occasions when leaks develop around the valves and/or the plugs. Therefore, it has been necessary in the past to provide apparatus for control of any leak which may occur in the end members of the cylinder.
Referring to FIG. 2, a mechanism 20 for controlling the leaks in the end of the cylinder 10 is shown. The mechanism 20 has a plurality of members 26 that are held in their relative positions by screws 21. The mechanism 20 can be expanded or contracted. These members 26 permit the apparatus to engage the constricted portion of the cylinder walls 17A and to be held in place resisting the force created by the leaking gas. A hood 22 can be used to cover the valves 14 and the surrounding area. A vent 23 is provided in hood 22 to permit the release of gas under controlled conditions. A screw 27 is used to apply pressure to the hood 22 and to force the hood against the end members 11 sufficient pressure to prevent escape of gas from the lower edges of the hood 22. Other mechanisms can be used to engage the fusible plugs and to prevent chemicals leaking from the vicinity of the plug from escaping to the surrounding environment. These mechanisms are generally satisfactory only for containing chemicals escaping in the vicinity of the fusible plugs and/or the values of the ton container. In practice, as will be seen by perusal of FIG. 2, considerable amount of time and effort are required to engage the repair mechanism 20 with the cylinder walls and to position the appropriate screws with respect to the valves to contain escaping chemicals. Despite protective clothing, it is desirable that this operation be performed as rapidly as posible and should require as little skill as possible. In addition, a multiplicity of repair devices are now required depending if the leak is from the vicinity of a valve or from a fusible plug.
A need has therefore been felt for a method and for an apparatus capable of temporary repair of the end members of ton cylinders that would be convenient to couple to the ton cylinder with requirement of training and that would contain, on a temporary basis, chemicals leaking from either the vicinity of fusible plugs or from the vicinity of the chemical valves or any other portion of the ton container or member.